Prescribing a medication or other therapy is as much art as science. Efforts to use blood-based tests for biomarkers and genetic tests to better match treatments to patients make sense. Psychiatrists are joining the chorus in calling for — and exploring — such tests. Yet this approach hasn’t paid off for psychiatry, and is elbowing aside other opportunities to help patients today.

No medication is perfect, and any doctor can tell you that certain treatments don’t work for certain patients. So-called precision medicine tests can help identify whether or not individuals will respond to a treatment.